阅读说明：本技术 一种2-酰基呋喃的制备方法 (Preparation method of 2-acylfuran ) 是由 姜维强 陈朝晖 韩勇 于 2019-08-15 设计创作，主要内容包括：本发明涉及一种2-酰基呋喃的制备方法,其特征在于包括以下步骤：(1)控制温度在-10～40℃,将70～98%水相或10～90%水相与有机相混合液、0.0001～2.0%锇化合物、0.001～5.0%胺类化合物加入反应容器中形成反应液；(2)将反应液打入密闭反应器中,换气为反应提供有氧环境；(3)向密闭反应器中加入1-(2-呋喃基)-1-烷基甲醇,控制压力0～20MPa、温度0～200℃、时间1～74小时；(4)反应停止后降温至室温,泄压至大气压,加入硫酸氢钠和醋酸萃取,有机相减压蒸馏精制得2-酰基呋喃产品。本发明的优点：本方法避免了现有合成路线中技术经济性缺点,减化了工艺流程,减少了消耗和排放,降低了能耗和成本,适合于扩大产能的工业化生产。(The invention relates to a preparation method of 2-acylfuran, which is characterized by comprising the following steps: (1) controlling the temperature to be-10-40 ℃, and adding 70-98% of water phase or 10-90% of mixed liquid of the water phase and the organic phase, 0.0001-2.0% of osmium compound and 0.001-5.0% of amine compound into a reaction vessel to form reaction liquid; (2) pumping the reaction liquid into a closed reactor, and ventilating to provide an aerobic environment for the reaction; (3) adding 1- (2-furyl) -1-alkyl methanol into a closed reactor, and controlling the pressure to be 0-20 MPa, the temperature to be 0-200 ℃ and the time to be 1-74 hours; (4) after the reaction is stopped, cooling to room temperature, decompressing to atmospheric pressure, adding sodium bisulfate and acetic acid for extraction, and carrying out vacuum distillation and rectification on the organic phase to obtain the 2-acyl furan product. The invention has the advantages that: the method avoids the technical economy defect in the existing synthesis route, simplifies the process flow, reduces the consumption and the emission, reduces the energy consumption and the cost, and is suitable for the industrial production of enlarging the productivity.)

1. A method for preparing 2-acyl furan is characterized by comprising the following steps:

(1) Controlling the temperature to be-10-40 ℃, adding 70-98% of water phase or 10-90% of mixed liquid of the water phase and an organic phase, 0.0001-2.0% of osmium compound and 0.001-5.0% of amine compound as a catalytic assistant into a reaction vessel by mol based on 1- (2-furyl) -1-alkyl methanol, uniformly stirring to form a reaction liquid, wherein the water phase is a phosphate buffer solution with the concentration of 0.001-5 mol/L and the pH value of 6-14, the organic phase is one or a mixture of two of aliphatic ether, aromatic or aliphatic hydrocarbon, tertiary alcohol, ester, halogenated hydrocarbon, dialkyl sulfoxide and N, N-dialkyl amide, and the volume of the organic phase in the mixed liquid of the water phase and the organic phase is 0.01-3 times of the volume of the water phase;

(2) Sealing the reactor or pumping the reaction solution in the step (1) into the sealed reactor, and connecting an air source to perform reaction gas replacement to provide an aerobic environment for the reaction;

(3) Adding 1- (2-furyl) -1-alkyl methanol into the closed reactor in the step (2), controlling the reaction pressure to be 0-20 MPa, the reaction temperature to be 0-200 ℃, and the reaction time to be 1-74 hours;

(4) After the reaction is stopped, cooling to room temperature, releasing pressure to atmospheric pressure, respectively adding sodium bisulfate with the mass of 0.005-5.0% of that of the reaction product and acetic acid with the mass of 0.01-10.0% of that of the reaction product into the reaction product for extraction, wherein the adding amount is the amount of the reaction product, and the organic phase is refined by adopting a reduced pressure distillation mode to prepare the 2-acyl furan product.

2. The process for producing a 2-acylfuran according to claim 1, wherein: the phosphate buffer solution in the step (1) is a buffer solution prepared from sodium phosphate or potassium phosphate, wherein the concentration of phosphate is preferably 0.02-1 mol/L, and the pH value of the solution is preferably 8-11.

3. The process for producing a 2-acylfuran according to claim 1, wherein: the organic phase of step (1) is preferably a tertiary alcohol or ester.

4. The process for producing a 2-acylfuran according to claim 1, wherein: the organic phase in the step (1) is tert-butyl alcohol or ethyl acetate.

5. The process for producing a 2-acylfuran according to claim 1, wherein: the amine compound in the step (1) is any one of tetraalkylammonium salt, tertiary amine, N-alkyl pyrrolidone, pyridine, bipyridine, quinoline and quinoline derivative.

6. The process for producing a 2-acylfuran according to claim 1, wherein: the amine compound in the step (1) is preferably tetrabutylammonium salt.

7. the method for preparing 2-acylfuran according to claim 1, wherein osmium compound in step (1) is one or more of OsO ₄, K ₂ OsO ₄. mu.2H ₂ O, Na ₂ OsO ₄. mu.2H ₂ O, Os ₃ (CO) ₁₂, OsCl ₃, H ₂ OsCl ₅, Na ₂ OsCl ₆. mu.nH ₂ O.

8. The method for preparing 2-acylfuran according to claim 1, wherein the osmium compound in step (1) is preferably OsO ₄, K ₂ OsO ₄. mu.2H ₂ O or Na ₂ OsCl ₆. mu.nH ₂ O.

9. the process for producing a 2-acylfuran according to claim 1, wherein: the dosage of the osmium compound in the step (1) is preferably 0.005-0.05% of the molar amount of the 1- (2-furyl) -1-alkyl methanol.

10. The process for producing a 2-acylfuran according to claim 1, wherein: the reaction pressure in the step (3) is preferably 0.1-2 MPa, the reaction temperature is preferably 40-120 ℃, and the reaction time is preferably 4-24 hours.

Technical Field

The invention belongs to the field of preparation of organic synthesis intermediates and fine chemical intermediates, and relates to a preparation method of 2-acylfuran.

Background

2-acyl furan, such as 2-acetylfuran, is an important organic synthesis intermediate and food additive, can be used for synthesizing various medical and chemical products including furan amine salt, and can also be used in the food industry, such as coffee, meat flavor type edible essence, soup, meat, seasoning and baked food as an additive.

According to the literature, the 2-acyl furan is synthesized by mainly using acid anhydride or acyl chloride to perform acylation reaction with furan under the action of a Lewis acid catalyst. Including boron trifluoride acetate anhydride method (J.A. C.S. 1949, 71, 1207-09, and US2515123,1950.), acetic anhydride methylbenzenesulfonic acid monohydrate method (JP 61-53275,1986, Heterocycles 1976,4 (5),1021-4, and chemical engineering Regulation 2015 9, 134, 136), acetic anhydride anhydrous zinc chloride method (J.A. C.S. 1947, 69, 1012-13, Tianjin chemical engineering 1998, 40-41, and Chemicals 2001, 23(6), 370-371), acetyl chloride p-methylbenzenesulfonic acid method (J.Org. Chem 1971, (4), 36.), acetic anhydride metal ion-exchanged clay method (US 74741), acetic anhydride phosphoric acid method 2015 6217, 2015 6216, 17, etc.

Compared with the synthesis methods, the expensive furan is used to obtain 2-acylfuran through acylation reaction, and furan is generally obtained by hydrogenation decarboxylation of furfural, so that decarboxylation and reacylation are uneconomical from the atom economy point of view. In addition, because of the limitation of decarboxylation reaction yield and productivity, the obtained furan is high in price, so that the cost of the 2-acylfuran obtained by the synthesis methods is high. Therefore, it is necessary to find a more suitable synthesis method of 2-acylfuran.

Disclosure of Invention

The invention aims to solve the problems of higher cost and insufficient economy of the existing 2-acylfuran synthesis process, and provides a preparation method of 2-acylfuran. The method directly adopts 1- (2-furyl) -1-alkyl methanol (alkyl is methyl and ethyl) prepared by reacting furfural with Grignard reagent as raw material, and uses oxygen to directly oxidize the 1- (2-furyl) -1-alkyl methanol in a water phase or the water phase and an organic phase under the condition that an osmium compound is used as a catalyst to prepare the 2-acyl furan.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

A method for preparing 2-acyl furan is characterized by comprising the following steps:

(1) Controlling the temperature to be-10-40 ℃, adding 70-98% of water phase or 10-90% of mixed liquid of water phase and organic phase, 0.0001-2.0% of osmium compound and 0.001-5.0% of catalytic auxiliary amine compound (improving the oxidation reaction selectivity of the catalyst, the activity of the catalyst and the reaction yield) into a reaction vessel according to the molar amount of 1- (2-furyl) -1-alkyl methanol, uniformly stirring to form a reaction liquid, wherein the water phase is a phosphate buffer solution (buffer solution prepared by sodium phosphate or potassium phosphate) with the concentration of 0.001-5 mol/L and the pH value of 6-14, the organic phase is one or a mixture of two of aliphatic ether, aromatic or aliphatic hydrocarbon, tertiary alcohol, ester, halogenated hydrocarbon, dialkyl sulfoxide and N, N-dialkyl amide, and the volume of the organic phase in the mixed solution of the water phase and the organic phase is 0.01-3 times of that of the water phase;

(2) Sealing the reactor or pumping the reaction solution in the step (1) into the sealed reactor, and connecting an air source (the oxygen concentration is higher than 10%) to perform reaction gas replacement so as to provide an aerobic environment for the reaction;

(3) Adding 1- (2-furyl) -1-alkyl methanol (the preparation method is shown in examples 1 and 2) into the closed reactor in the step (2), controlling the reaction pressure to be 0-20 MPa, the reaction temperature to be 0-200 ℃, and the reaction time to be 1-74 hours;

(4) Cooling to room temperature after the reaction is stopped, releasing the pressure to atmospheric pressure, respectively adding sodium bisulfate with the mass of 0.005-5.0% of that of the reaction product and acetic acid with the mass of 0.01-10.0% of that of the reaction product into the reaction product for extraction, and refining the organic phase by adopting a reduced pressure distillation mode to prepare the 2-acylfuran product.

Further, the concentration of the phosphate in the phosphate buffer solution in the step (1) is preferably 0.02-1 mol/L, and the pH value of the solution is preferably 8-11.

Further, the organic phase of step (1) is preferably a tertiary alcohol or ester.

further, the organic phase in the step (1) is tert-butyl alcohol or ethyl acetate.

Further, the amine compound in the step (1) is any one of tetraalkylammonium salt, tertiary amine, N-alkyl pyrrolidone, pyridine, bipyridine, quinoline and quinoline derivative.

Further, the amine compound of step (1) is preferably a tetrabutylammonium salt.

Further, the osmium compound in step (1) is one or more of OsO ₄, K ₂ OsO ₄. sup.2H ₂ O, Na ₂ OsO ₄. sup.2H ₂ O, Os ₃ (CO) ₁₂, OsCl ₃, H ₂ OsCl ₅, Na ₂ OsCl ₆. sup.nH ₂ O.

Further, the osmium compound in step (1) is preferably OsO ₄, K ₂ OsO ₄. cndot.2H ₂ O or Na ₂ OsCl ₆. cndot.H ₂ O.

further, the amount of the osmium compound charged in the step (1) is preferably 0.005 to 0.05% based on the molar amount of the 1- (2-furyl) -1-alkylmethanol.

Further, the reaction pressure in the step (3) is preferably 0.1-2 MPa, the reaction temperature is preferably 40-120 ℃, and the reaction time is preferably 4-24 hours.

Mixing reaction raw materials (water phase or water phase + organic phase, catalyst and catalyst auxiliary agent) at low temperature, adding the mixture into a closed reactor, or adding the reaction raw materials into the closed reactor respectively at low temperature, introducing an oxygen gas source for gas replacement, adding 1- (2-furyl) -1-alkyl methanol, maintaining pressure and raising temperature for reaction, keeping the system pressure stable until the gas source is closed, keeping the pressure in the closed reactor unchanged for a long time, and stopping the reaction.

The invention has the advantages that: the preparation method adopts the raw material of 1- (2-furyl) -1-alkyl methanol prepared by the reaction of furfural and Grignard reagent, the reaction yield is about 95 percent at present and is far higher than the reaction yield (generally 60 to 80 percent) of furan prepared by hydrogenation and decarboxylation of furfural, and oxygen is adopted in the oxidation reaction as an oxidant, and the solvent and the catalyst can be recycled, so that the preparation method has obvious cost advantage; after the reaction is finished, the solvent is recovered, and a finished product can be obtained by direct distillation, so that the difficulty of recovering the finished product in the later period is reduced; the preparation method avoids the technical economy defect in the existing synthesis route, simplifies the process flow, reduces the consumption and the discharge, reduces the energy consumption and the cost, and is suitable for the industrial production technology of expanding the productivity.

Drawings

FIG. 1 is a schematic diagram of one process for the preparation of 2-acylfurans according to the present invention;

FIG. 2 is a schematic diagram of a conventional process for preparing 2-acylfuran.

Detailed Description

The invention is further illustrated by combining fig. 1, a preparation method of 2-acylfuran, which comprises the following specific implementation steps: the starting materials 1- (2-furyl) -1-methylmethanol and 1- (2-furyl) -1-ethylmethanol used in the present invention were prepared in examples 1 and 2.